This invention relates to the use of a cutting wire, and particularly, to an apparatus and method for starting a cutting wire through a material to be cut with the wire.
Wire saws have been used to cut many types of materials. A wire saw consists of a length of suitable thin cutting wire and handles which may be connected at either end of the wire. In operation, the cutting wire is positioned so as to traverse the object or material to be cut and then the wire is reciprocated back and forth against the material using the handles to hold the wire. This reciprocating motion of the thin wire against the material cuts through the material.
Although wire saws are inexpensive to manufacture and are effective for many applications, they are not well suited for cutting a material that has no accessible edge. In order to cut a material having no accessible edge with a cutting wire, one end of the wire must be started or inserted through the material so that the handles may be attached and the desired reciprocating motion imparted. Starting or inserting the thin and flexible cutting wire through the material to be cut may be difficult or even impossible depending on the type of material.
For example, the sealant material with which a vehicle windshield is sealed within the windshield frame usually extends continuously around the entire perimeter of the glass and, therefore, has no accessible edge. In order to cut the windshield sealant material with a cutting wire, the cutting wire first had to be started through the material and then the handles connected on either side of the glass so that the wire could be reciprocated to provide the desired cutting action. However, it was very difficult and time consuming to insert one end of the wire through the tough and resilient sealant material. In some cases it was simply not possible to start the wire. In these cases either the glass had to be broken to provide an accessible edge to the sealant material or a hole had to be drilled through the material through which the cutting wire could be inserted. Both situations were unsatisfactory, the former because it was often desirable to save the glass intact and the latter because it was difficult to drill a suitable starting hole due to the limited work space around the windshield.